DCC -- you are not alone most of the time. Let me explain.
A "Normal" cow, one that has had a couple of heats prior, will actaully have about a 30 hours heat period. Of those 30 hours, 15-18 are REAL standing activity -- seeking out others to ride and will stand for them to mount. The rest of the time - early and late -- are what is called pre-estrous and post - estrous periods. That time frame will usually be when they run around trying to mount others, head butting and bellering like mad. They will do that before and after actaul stainding.
Depending on the weather conditions -- cool versus warm -- storm and fair skys and all that -- the actual standing will vary frmo cow to cow -- especially those darn hfrs.
I have never figured out why the research facilities can claim that a hfr will ovulate earlier than a cow -- I do not agree at all. A hfr MAY show actual standing heat -- instead of the pre-estrous activity -- earlier than a cow would and you would then think she is actually in. This will give you the impression - and rightfully so - that they stay in longer. The TRUE heat is not all that different than a cow, but they will most certainly show you it longer than a cow would. I have never really cared much for WHEN they started, I only care about when they FINISH and go lay down tired and worn out. That is when I figure when to breed them.
Possibly in your hfr's case here, she was showing true standing heat signs when in reality -- she was in pre-estrous and didn't know the routine. All she knew was that she was deffinately feeling frisky, and she wanted some action. Breeding her on this activity was too early -- doesn't matter what the research shows, I don't personally have any cows that can read research papers!!! hehehe
Bottom line -- your hfr showed you standing heat signs when she was actually in pre-estrous, and for that matter -- MAY have still stood for others when she was in post-estrous. They just don't know the routine yet. I would have waited to breed her till she quit doing any thing, which would have been LATE in the evening AFTER the morning you bred her. Last year I myself got in a hurry on 2 head, they both failed to settle -- and prior to that for several years -- we ran almost 100% (101 units for 100 pregnancies on 10 head per year) Last years, I used some Cidrs on a few , and that was when it went south. I usualy just natural breed them on thier given day -- so again -- don't fix it if it isn't broken! We have never had a bull either.
PATIENCE is worth a fortune~!!
Best of luck form here on -- give them TIME
Terry